css/css-flexbox/negative-overflow-003.html

<!DOCTYPE html>
<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1114306">
<meta name="assert" content="the correct scrollbars appear for sideways writing-mode flexboxes">

<style>
.container {
  width: 100px; height: 100px;
  overflow: scroll;
  border: solid 3px;
  display: inline-flex;
  padding: 10px;
  gap: 10px;
  align-items: start;
  margin: 10px;
  vertical-align: bottom;
}

.item {
  min-width: 110px; min-height: 110px;
  background: cyan;
}

.container:hover::before {
  position: fixed;
  top: 0; left: 0;
  font-size: 10px;
  content: attr(style);
  background: yellow;
  direction: ltr;
  writing-mode: horizontal-tb;
}
</style>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/check-layout-th.js"></script>
<body onload="checkLayout('.container')">
<script>
const writingModes = ['sideways-rl', 'sideways-lr'];
const directions = ['ltr', 'rtl'];
const flexDirections = ['row', 'row-reverse', 'column', 'column-reverse'];
const flexWraps = ['nowrap', 'wrap', 'wrap-reverse'];

for (let writingMode of writingModes) {
  for (let direction of directions) {
    for (let flexDirection of flexDirections) {
      for (let flexWrap of flexWraps) {
        let container = document.createElement('div');
        container.className = 'container';
        container.style.writingMode = writingMode;
        container.style.direction = direction;
        container.style.flexDirection = flexDirection;
        container.style.flexWrap = flexWrap;

        for (let i = 0; i < 3; i++) {
          let item = document.createElement('div');
          item.className = 'item';
          item.textContent = (i+1);
          container.appendChild(item);
        }

        let bias = flexWrap != 'nowrap';
        if (flexDirection == 'row' || flexDirection == 'row-reverse') {
          bias = !bias;
        }
        container.setAttribute('data-expected-scroll-width', bias ? 130 : 370);
        container.setAttribute('data-expected-scroll-height', bias ? 370 : 130);

        document.body.appendChild(container);
      }
    }
  }
}
</script>